Coherent motion sensitivity and reading development in the transition from prereading to reading stage.

Evidence suggests that sensitivity to coherent motion (CM) is related to reading, but its role in the etiology of developmental dyslexia remains unclear. In this longitudinal study, CM sensitivity was measured in 31 children at family risk for dyslexia and 31 low-risk controls. Children, diagnosed with dyslexia in third grade (mean age=8 years 3 months), demonstrated reduced CM sensitivity in kindergarten (mean age=5 years 8 months), before they had learned to read. Preschool CM thresholds in controls also uniquely predicted future literacy achievement. When reassessed in first grade, CM sensitivity in the dyslexic children was age appropriate, and CM thresholds in the controls no longer predicted literacy acquisition. These findings contribute to the debate about the developmental relations between visual processing and reading acquisition.